The Celtic lever harp (also called Irish harp or folk harp) has 34 diatonic strings tuned to a C major scale by default. Unlike a pedal harp, individual strings are sharpened by flipping lever mechanisms at the top of each string. ChordColor renders all 34 strings with the traditional color markers -- red for C strings and blue for F strings -- that harpists use for visual navigation on the real instrument. Interval colors are layered on top, showing the harmonic role of each string in the selected chord.
Because the harp is diatonic, changing keys requires flipping levers to sharpen specific strings. Moving from C major to G major means sharpening all the F strings. The interval visualization updates when levers are toggled, so you can see how the available chord voicings change as you set up for different keys. This is a practical tool for planning lever changes during a piece.
The red C and blue F string markers serve the same function on screen as they do on a physical harp -- they are landmarks that help you find your place across 34 strings without looking at individual string labels. Combined with interval coloring, you can quickly identify where chord tones fall and which strings to pluck for arpeggios, block chords, and glissando patterns.